1. Field of the Invention
The present invention relates to a self-aligning fixed grille for motor vehicles, especially for severe service trucks.
2. Description of the Prior Art
The internal combustion engine of a motor vehicle generates large quantities of heat during use. Air-cooled or liquid-cooled cooling systems remove the generated heat from the engine and other components of a motor vehicle.
One liquid cooling system uses a radiator in a coolant circuit with the engine for cooling a coolant or cooling water, and a water pump or a flow control valve to control the flow rate of the coolant that passes through the radiator. The cooling water receives heat from the engine, then returns to the radiator.
In such a cooling water system, a frontally placed radiator transfers heat from the circulating coolant by conductive transfer to ambient air flowing through the radiator. The frontal placement of the radiator takes advantage of ram air for forcing ambient air through the radiator when the vehicle is driven forward.
Unfortunately, the frontal placement of the radiator also makes the radiator vulnerable to debris, such as insects and mud. A large build-up of insects, for example, can interfere with heat exchange and reduce the efficiency of the cooling system.
Grilles are therefore used to prevent damage to the radiator from insects and other debris. A grille provides a portion of the exterior skin of a vehicle, protecting the components of the vehicle and streamlining the vehicle to reduce wind resistance. Grilles in some motor vehicles, such as automobiles, are typically affixed to the bumper of the vehicle. Other vehicles affix the grille to the hood.
The grille of a severe service vehicle, however, is usually stationary and hard mounted to the vehicle's cooling module or radiator. Severe service vehicles are used for construction, government, waste collection and other demanding on/off highway applications. Because severe service vehicles often require equipment mounted to extensions in the front of the vehicle as well as power to run the equipment from the engine, the cooling system is mounted above the frame rails to accommodate the equipment. Mounting the grille to the radiator rather than the front of the hood allows access to the engine compartment through the hood opening, especially when the hood cannot be fully lifted forward due to the presence of the equipment.
The hood typically fastens to the front of the chassis and to the back of the cab and moves relative to the vehicle's body in use. During assembly, the cooling module and the hood are often misaligned relative to one another. To accommodate for this misalignment, the hood and grille are separated by large gaps during use to prevent the front mounted equipment from crashing into the grille during use.
A large amount of adjustability is therefore built into the grille. For aesthetic reasons, however, there is not enough adjustability to compensate for all of the tolerance stack-up in assembly and still allow a sufficient gap between the hood and grille to prevent their contact during use. Because there is frequently a large amount of part interference and poor fit, the manufacture must spend additional money to fulfill the warranty requirements for grille realignment, premature damage and/or accepting the effects to fit and finish reputation.
Therefore, it would be advantageous to develop a grille that would be able to compensate for the tolerance stack-up during assembly while allowing a sufficient gap between the hood and grille to prevent their contact during use. It would be further advantageous to provide a grille that is well-aligned within the vehicle. Still another advantage is to provide a grille that would allow easy access to the engine compartment without fully raising the hood.